Does the job but slides down under its own weight, with the black non-transparent metal bar on the top, covering a few pixels of the screen real estate... very annoying! also, even though the packaging was intact, the filter wasn't perfectly flat but a bit embossed on one of the sides. I returned the product.
Pro
Does what it says it will do, limits the FOV and makes the screen black from anything above 30 deg
Two sides offer matte and gloss options
Magnetic and attaches to the MB sans adhesives!
Contra
Magnetic and doesn't stay in place - slides down a bit covering part of the screen
Magnetic at the top only meaning you have to be quick when closing the lid